My materials seem to be locked on one colour?
I think I have an idea what you are referring to. You are duplicating an object and changing the materials of the properties, correct?

When you go to the material of the duplicated it might look like this "Material.002 and then a box that says "2" next to it before the "F""+""x". Click on the number (which is 2) and do so on texture as well if necessary. I hope that helps, as that was my solution.